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authorNicholas Piggin <npiggin@gmail.com>2019-04-11 13:34:46 +1000
committerIngo Molnar <mingo@kernel.org>2019-05-03 19:42:58 +0200
commit9ca12ac04bb7d7cfb28aa549dcd3d15761f15543 (patch)
tree98dbad7e8c82eea820041cdf693d02b919d0ecc1 /kernel/power
parent2f1a6fbbef7781382850c3104ecb658f21b5d460 (diff)
kernel/cpu: Allow non-zero CPU to be primary for suspend / kexec freeze
This patch provides an arch option, ARCH_SUSPEND_NONZERO_CPU, to opt-in to allowing suspend to occur on one of the housekeeping CPUs rather than hardcoded CPU0. This will allow CPU0 to be a nohz_full CPU with a later change. It may be possible for platforms with hardware/firmware restrictions on suspend/wake effectively support this by handing off the final stage to CPU0 when kernel housekeeping is no longer required. Another option is to make housekeeping / nohz_full mask dynamic at runtime, but the complexity could not be justified at this time. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rafael J . Wysocki <rafael.j.wysocki@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linuxppc-dev@lists.ozlabs.org Link: https://lkml.kernel.org/r/20190411033448.20842-4-npiggin@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/Kconfig9
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index f8fe57d1022e..9bbaaab14b36 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -114,6 +114,15 @@ config PM_SLEEP_SMP
depends on PM_SLEEP
select HOTPLUG_CPU
+config PM_SLEEP_SMP_NONZERO_CPU
+ def_bool y
+ depends on PM_SLEEP_SMP
+ depends on ARCH_SUSPEND_NONZERO_CPU
+ ---help---
+ If an arch can suspend (for suspend, hibernate, kexec, etc) on a
+ non-zero numbered CPU, it may define ARCH_SUSPEND_NONZERO_CPU. This
+ will allow nohz_full mask to include CPU0.
+
config PM_AUTOSLEEP
bool "Opportunistic sleep"
depends on PM_SLEEP